Cartridge ejection device for an explosion driven setting gun

ABSTRACT

In an explosion driven setting gun, spent cartridges are ejected from a cartridge chamber by a pivotally mounted ejection lever when a front part of the gun containing the cartridge chamber is pivoted relative to a rear part. To assure proper ejection, during the pivotal movement as the gun parts are opened, a locking member holds the ejection lever until a spring biased stop member exerts a predetermined load on the ejection lever causing it to be released from the locking member. Upon such release, the spring biasing action of the stop member causes an accelerated pivotal movement of the ejection lever with the resultant ejection of a spent cartridge.

United States Patent [191 Jochum 1 CARTRIDGE EJECTION DEVICE FOR ANEXPLOSION DRIVEN SETTING GUN [75] Inventor: Peter Jochum, Meiningen,Austria [73] Assignees Hilti Aktiengesellschaft [22] Filed: May 30, 1973211 App]. No.: 365,059

[30] Foreign Application Priority Data June 7, 1972 Germany 2227775 [52]US Cl. 227/9 [51] Int. Cl. B25c 1/08 [58] Field of Search 227/8, 9, 10,ll

[56] References Cited UNITED STATES PATENTS 2,804,620 9/1957 Gannon227/9 3,216,140 11/1965 Termet 227/10 X Bayer 227/9 51 May 13, 1975Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, orFirm-Toren, McGeady and Stanger I [57] ABSTRACT In an explosion drivensetting gun, spent cartridges are ejected from a cartridge chamber by apivotally mounted ejection lever when a front part of the gun containingthe cartridge chamber is pivoted relative to a rear part. To assureproper ejection, during the pivotal movement as the gun parts areopened, a locking member holds the ejection lever until a spring biasedstop member exerts a predetermined load on the ejection lever causing itto be released from the locking member. Upon such release, the springbiasing action of the stop member causes an accelerated pivotal movementof the ejection lever with the resultant ejection of a spent cartridge.

5 Claims, 2 Drawing Figures 1 CARTRIDGE EJECTION DEVICE FOR AN EXPLOSIONDRIVEN SETTING GUN SUMMARY OF THE INVENTION The present invention isdirected to a cartridge ejection device for an explosion driven settinggun for driving fastening elements into a hard target material, such asteel, concrete and the like, and, more particularly, it concerns thearrangement of a locking member which secures a cartridge ejection leverin position until a predetermined load is exerted on the lever.

Fastening element setting guns have used a two-arm ejector leverpivotally mounted on a part of the gun for removing a spent cartridgelodged within a cartridge chamber. One arm of the lever extends underthe bottom edge of the cartridge and the other arm cooperates with astop for limited displacement against the force of a spring during thepivotal movement of that part of the gun containing the cartridgechamber about an axis transverse to the longitudinal axis of the gun,relative tothe part of the gun containing the ignition mechanism.

A fastening element setting gun of the above type is disclosed in theGerman Offenlegungsschrift 1,703,523. In these known guns, a stopmounted in an oblong slot guide parallel to the longitudinal axis of thegun, is prestressed against the action of a spring during the pivotalmovement of the two gun parts. The prestressed stop acts as an ejectorlever extending under the bottom edge of the cartridge to eject it fromthe cartridge chamber during the progressive pivotal movement of the twogun parts.

In practice, it has been found that, depending on the strength of thepropellent charge used, the cartridges are lodged more or less firmly inthe cartridge chamber. Frequently and especially with a low propellentcharge strength, the cartridge located in the cartridge chamber is onlyloosened by the stop prestressed by the spring and the desired ejectiondoes not take place. The failure to eject the cartridge is dueparticularly to the fact that the ejection lever is actuated by the stopbefore the spring is completely tightened or compressed and, as aresult, the cartridge is only partly ejected, and the remaining springforce is insufficient to dislodge the cartridge completely during theprogressive pivotal movement of the two gun parts.

Therefore, the primary object of the present invention is to provide adevice in a fastening element setting gun which assures the safe andcomplete ejection of spent cartridges.

In accordance with the present invention the ejection lever is locked inposition by means of a locking member disposed on the gun partsupporting the ejection lever and displaceably secured within a detentin the ejection lever. The locking member projects into the pivotalrange of the detent and it is disengaged from the detent when apredetermined load acts on the ejection lever.

By using such a locking member, independent of the manner in which thecartridge is held within the cartridge chamber, the stop is alwaysstressed equally by the restoring force of the spring for assuringdislodgement of the spent cartridge. Particularly during the initialphase of the pivotal movement of the two gun parts, that is, from theclosed to the open condition, the stop is displaced to the full extentagainst the spring so that, with the progressive pivotal movement of thetwo gun member. In addition, it has been found to be particularlysuitable to use an annular spring as the spring element which ispositioned on the rear part of the barrel and projects into the pivotalrange of the detent formed on the ejection lever.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which there is illustrated and described a preferredembodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a side view, partly in section, of a portion of a fasteningelement setting gun, embodying the present invention, with two parts ofthe gun pivoted relative to one another so that a spent cartridge isabout to be dislodged; and

FIG. 2 is a sectional view showing a portion of the two gun partsillustrated in FIG. 1 with the ejection of the cartridge havingcommenced.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 a fastening elementsetting gun is illustrated consisting of a front gun part 1 and a reargun part 2 with the two parts pivotally interconnected. Gun part 1 ispivotally mounted on a bolt 3 located in the rear gun part 2 and itcontains a barrel 4 arranged for axial displacement. The rear end of thebarrel 4 contains a cartridge chamber 5 and an ejection lever 6. Theejection lever 6 is pivotally mounted on a pin 7 and consists of twoarms 6a, 6b extending angularly to one another, that is, with the arm 6aextending transversely of the axial direction of the barrel and theother arm 6b extending generally in parallel with the longitudinal axisof the barrel. The free end of the arm extends under the bottom edge 8aof a cartridge casing 8 and the other arm 6b is placed in operativeconnection with a stop 11, located in the rear gun part 2, when the gunparts are pivoted from the closed to the opened position. On the barrel,adjacent its end containing the cartridge chamber 5, an annular spring 9is mounted in a groove 4a. The annular spring 9 projects into thepivotal range of a detent 6c formed in the free end of the arm 6b of theejection lever 6.

As can be noted from the illustration provided in FIGS. 1 and 2, thestop 11 is mounted in gun part 2 for a limited axial movement. To affordthe limited axial movement, the stop, which extends in the axialdirection of the gun part, is mounted on the same pivot bolt or pin 3which interconnects the two gun parts. The pivot pin 3 extends throughan oblong slot 11a in the stop with the slot elongated in the axialdirection of the stop. At its rearward end, and the stop butts against aspring 12 fitted into the gun part 2.

Procedure for Ejecting a Spent Cartridge After a fastening element hasbeen inserted, the gun is removed from the target material and the frontgun part 1 is pivoted, relative to the rear gun part 2, in the directionof the arrow F. During this swiveling or pivotal movement, the arm 6b,previously extending in the axial direction of the gun part 2 isdisplaced into a position so that it extends transversely of the axialdirection of gun part 2 and comes into operative connection with theforward end of the stop 11. At this point, the ejection lever is held inposition by the engagement of the annular spring 9 within the detent 60at the free end of the arm 6b. Accordingly, the ejection lever issecured against pivotal movement about the pivot pin 7 and offersresistance to the stop 11 during the continued pivotal movement betweenthe two gun parts. The action of the ejection lever 6 on the stop 11causes it to move rearwardly against the force of the spring 12 untilits movement is halted by contact between the end of the oblong slot 11aand the pivot bolt 3. This position is illustrated in FIG. 1, that is,the maximum spring bias is acting on the stop but the locking action onthe ejection lever 6 has not been released.

With the continued pivotal movement of gun part 1 relative to gun part2, the reaction between the stop 11 and the pivot bolt 3 produces asudden increase in pressure by the stop on the arm 6b of the ejectionlever 6 so that the detent 6c causes the annular spring 9 to yield andrelease the lever. Accordingly, the force compressing the spring 12 isreleased and a sudden accelerated pivotal movement of the ejection levertakes place with the free end of the arm 6a lifting the spent cartridge8 out of the cartridge chamber 5. In FIG. 2 the stop ll is showndisplaced by the spring 12 so that the pivot bolt 3 contacts theopposite end of the oblong slot 11a from that shown in FIG. 1 and theejection lever is commencing its pivotal movement about the pin 7 fordislodging the spent cartridge.

To load the gun and return it to the firing condition, a live cartridgeis placed in the cartridge chamber and, during subsequent pivotalmovement of the gun part 1 relative to the gun part 2 in the directionopposite to the direction of the arrow F, the end face 2a of the gunpart automatically effects a complete insertion of the cartridge intothe cartridge chamber and returns the ejection lever 6 into its startingposition. When the reverse pivotal movement of the gun parts relative toone another has been completed the gun is again in the loaded or firingcondition.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the inventiveprinciples, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

l. Explosion driven setting gun for driving fastening elements into aharg target material, such as steel, concrete and the like, comprising afirst gun part and a second gun part pivotally interconnected to oneanother so that the gun can be displaced between an open condition and aclosed condition by pivotally displacing said gun parts relative to oneanother, a cartridge chamber formed in said first gun part, a two-armejection lever pivotally mounted on said first gun part for displacing aspent cartridge lodged in said cartridge chamber and having a first armand a second arm extending angularly from said first arm, a springbiased stop assembly mounted on said second gun part, said first arm ofsaid lever arranged to extend under the bottom edge of a cartridgewithin said cartridge chamber and said second arm arranged to cooperatewith said stop assembly in the opened position of the gun so that saidstop assembly pivots said lever so that said first arm dislodges a spentcartridge from the cartridge chamber, wherein the improvement comprisesthat said second arm has a detent formed therein, and an annularresilient locking member encircling and mounted on the outer surface ofsaid first gun part and extending outwardly therefrom into the pivotalrange of said detent and being displaceably lockably engageable withinsaid detent for gripping said ejection lever against pivotabledisplacement so that said first arm is held in position ready todislodge a spent cartridge as the gun is moved to the open condition,and said locking member being displaceable from said detent under theapplication of a predetermined load on said second arm from said stopassembly as said gun is displaced into the open condition.

2. Explosion driven setting gun, as set forth in claim 1, wherein saidtwo-arm ejection lever is pivotably mounted on said first gun part atthe juncture of said first and second arms, said first arm extendingtransversely of the axis of the cartridge chamber and said second armextending approximately parallel to the axis of said cartridge chamber,said detent located adjacent the end of said second arm spaced from thejuncture of said first and second arms, and said stop assembly contactssaid second arm intermediate the juncture of said first and second armsand said detent.

3. Explosion driven setting gun, as set forth in claim 1, wherein saidlocking member is a spring element.

4. Explosion driven setting gun, as set forth in claim 1, wherein saidstop assembly comprises a stop having an oblong opening, a pivot pinmounted in said second gun part and extending through the oblong slot insaid stop, and a spring positioned in said second gun part and biasingsaid stop toward said second arm of said ejection lever when said gun ispivoted into the open position.

5. Explosion driven setting gun, as set forth in claim 4, wherein saidpivot pin pivotally interconnects said first and second gun parts.

1. Explosion driven setting gun for driving fastening elements into a harg target material, such as steel, concrete and the like, comprising a first gun part and a second gun part pivotally interconnected to one another so that the gun can be displaced between an open condition and a closed condition by pivotally displacing said gun parts relative to one another, a cartridge chamber formed in said first gun part, a two-arm ejection lever pivotally mounted on said first gun part for displacing a spent cartridge lodged in said cartridge chamber and having a first arm and a second arm extending angularly from said first arm, a spring biased stop assembly mounted on said second gun part, said first arm of said lever arranged to extend under the bottom edge of a cartridge within said cartridge chamber and said second arm arranged to cooperate with said stop assembly in the opened position of the gun so that said stop assembly pivots said lever so that said first arm dislodges a spent cartridge from the cartridge chamber, wherein the improvement comprises that said second arm has a detent formed therein, and an annular resilient locking member encircling and mounted on the outer surface of said first gun part and extending outwardly therefrom into the pivotal range of sAid detent and being displaceably lockably engageable within said detent for gripping said ejection lever against pivotable displacement so that said first arm is held in position ready to dislodge a spent cartridge as the gun is moved to the open condition, and said locking member being displaceable from said detent under the application of a predetermined load on said second arm from said stop assembly as said gun is displaced into the open condition.
 2. Explosion driven setting gun, as set forth in claim 1, wherein said two-arm ejection lever is pivotably mounted on said first gun part at the juncture of said first and second arms, said first arm extending transversely of the axis of the cartridge chamber and said second arm extending approximately parallel to the axis of said cartridge chamber, said detent located adjacent the end of said second arm spaced from the juncture of said first and second arms, and said stop assembly contacts said second arm intermediate the juncture of said first and second arms and said detent.
 3. Explosion driven setting gun, as set forth in claim 1, wherein said locking member is a spring element.
 4. Explosion driven setting gun, as set forth in claim 1, wherein said stop assembly comprises a stop having an oblong opening, a pivot pin mounted in said second gun part and extending through the oblong slot in said stop, and a spring positioned in said second gun part and biasing said stop toward said second arm of said ejection lever when said gun is pivoted into the open position.
 5. Explosion driven setting gun, as set forth in claim 4, wherein said pivot pin pivotally interconnects said first and second gun parts. 